1. Field of the Invention
The present invention relates to a high-current fuse for vehicles which can restrict a temperature rise when energized.
2. Description of the Related Art Japanese Patent Application Laid-Open No. 610-66387 discloses a fuse 90 shown in FIG. 26.
The fuse 90 comprises a pair of tab-like terminals 91, a fusible element 92 disposed between the tab-like terminals 91, and a resin frame 93 integrally formed around the fusible element 92. The resin frame 93 is rectangular and includes the connecting portion between the tab-like terminals 91 and the fusible element 92. If the value of a rated current J' flowing through the tab-like terminals 91 is too large, the fusible element 92 generates heat and fuses with the heat. By doing so, excess current can be prevented from flowing into an auxiliary equipment (not shown) connected to the tab-like terminals 91.
However, since the heat generated from the fusible element 92 is transmitted to the resin frame 93, which is in contact with the fusible element 92, there is always a possibility that the resin frame 93 melts. To prevent this, it is necessary to put restrictions on environments and conditions in which the fuse 90 can be used, and the rated current J' flowing through the fuse 90.
Also, if the fuse 90 is placed in a high-temperature condition, tensile stress and compressive stress act directly upon the fusible element 92 due to the difference in linear expansion coefficient between the tab-like terminals 91 and the resin frame 93, thereby reducing the durability of the fuse 90.
There has also been disclosed a fuse box 94 having a fuse as shown in FIG. 27.
The fuse box 94 comprises a main box 95, an L-shaped bus bar 96 connected to a side wall of the main box 95, and a cover 97 attached below the main box 95. The main box 95 is fixed to one end of the bus bar 96, and a battery connecting portion 95a is attached to the other end of the bus bar 96. The battery connecting portion 95a is connected to the battery post 98a of a battery (storage battery) 98. A fuse 99 is inserted into the upper portion of the main box 95, and a terminal (not shown) for the fuse 99 is inserted into the lower portion of the main box 95.
However, the production cost of the fuse box 94 is high due to the large number of components. Also, the fuse box 94 has a drawback that the length between the battery connecting portion 95a and the fuse 99 is too long, because the fuse 99 is arranged in line with the bus bar 96. Accordingly, there is always a possibility that the fuse box 94 becomes too big in size.